N-(2-hydroxy-higher hydrocarbyl)-n-lower hydrocarbyl-aminocarboxylates

ABSTRACT

N-(2-HYDROXY-HIGHER HYDROCARBYL)-N-LOWER HYDROCARBYL-AMINOCARBOXYLATES OR THE CORRESPONDING AMINOCARBOXYLIC ACIDS ARE OF THE FORMULA   R1-CH(-OH)-CH2-N(-R2)-R3-COO-X   WHEREIN R1 IS AN ALIPHATIC HYDROCARBON RADICAL OF 10 TO 20 CARBON ATOMS, R2 IS A HYDROCARBON RADICAL OF 1 TO 4 CARBON ATOMS, R3 IS A DIVALENT ALIPHATIC OR AROMATIC HYDROCARBON RADICAL OF 1 TO 9 CARBON ATOMS, AND X IS EITHER HYDROGEN OR A SALT-FORMING ELEMENT OR RADICAL. IN PREFERRED ENBODIMENTS OF THE INVENTION, R1 IS AN ACYCLIC SATURATED RADICAL OF 12 TO 16 CARBON ATOMS, R2 IS METHYL, R3 IS OF 1 TO 2 CARBON ATOMS, AND X IS A MONOVALENT METAL OR AN ALKANOLAMINE, SUCH AS SODIUM OR TRIETHANOLAMINE. THE NOVEL COMOUNDS ARE SURFACE ACTIVE AND MANY EXHIBIT EXCELLENT SUBSTANTIVITIES TO FIBROUS MATERIALS, ESPECIALLY COTTON. THEY ARE USEFUL AS DETERGENTS OR AS CONSTITUENTS OF DETERGENT PREPARATIONS. PREFERRED COMPOUNDS FUNCTION VERY EFFECTIVELY AS SOFTENING AGENTS, WHICH MAY BE EMPLOYED IN THE FINAL RINSING OF LAUNDRY OR TEXTILES, IF USED ALONE OR IN CONJUNCTION WITH OTHER DETERGENT COMPOSITION MATERIALS, IN THE WASH WATER. THE PRESENT N-(2HYDROXY-HIGHER HYDROCARBYL)-N-LOWER HYDROCARBYL-AMINOCARBOXYLATES MAY ALSO BE CONVERTED TO THE CORRESPONDING N-OXIDES, WHICH ARE ALSO EFFECTIVE DETERGENTS, AND MANY OF WHICH MAY BE EMPLOYED AS EXCELLENT SOFTENING AGENTS FOR LAUNDRY AND TEXTILES.

United States Patent 3,755,435 N-(Z-HYDROXY-HIGHER HYDROCARBYL)- N LOWER HYDROCARBYL AMINOCAR- BOXYLATES Bjorn Sundby, Piscataway, Edward J. Kenney, Bernardsville, and Harold E. Wixon, New Brunswick, N.J., assiguors to Colgate-Palmolive Company, New York,

l 'lo'nrawin Filed Nov. 28, 1969, Ser. No. 880,991 Int. (:1. C07c 101/06 US. Cl. 260-534 M 6 Claims ABSTRACT OF THE DISCLOSURE N-(Z-hydroxy-higher hydrocarbyl)-N-lower hydrocarbyl-aminocarboxylates or the corresponding aminocarboxylic acids are of the formula RICH(OH)CHQ-I!IR3COOX wherein R is an aliphatic hydrocarbon radical of to 20 carbon atoms, R is a hydrocarbon radical of 1 to 4 carbon atoms, R is a divalent aliphatic or aromatic hydrocarbon radical of 1 to 9 carbon atoms, and X is either hydrogen or a salt-forming element or radical. In preferred embodiments of the invention, R is an acyclic sat urated radical of 12 to 16 carbon atoms, R is methyl, R is of 1 to 2 carbon atoms, and X is a monovalent metal or an alkanolamine, such as sodium or triethanolamine.

The novel compounds are surface active and many exhibit excellent substantivities to fibrous materials, especially cotton. They are useful as detergents or as constituents of detergent preparations. Preferred compounds function very effectively as softening agents, which may be employed in the final rinsing of laundry or textiles, if used alone or in conjunction with other detergent composition materials, in the wash water. The present N-(2- hydroxy-higher hydrocarbyD-N-lower hydrocarbyl-aminocarboxylates may also be converted to the corresponding N-oxides, which are also effective detergents, and many of which may be employed as excellent softening agents for laundry and textiles.

This invention relates to novel N-(2-hydroxy-higher hydrocarbyl)-N-lower hydrocarbyl-aminocarboxylates and the corresponding aminocarboxylic acids. These compounds have been found to be useful surface active materials and many are substantive to a wide variety of fibrous substances, such as cotton, wool and synthetic textiles. Thus, the invented compounds may be employed as emulsifiers, solubilizers for lipophilic compounds, as wetting agents, detergents and also, in many cases, as softeners for textiles. They are also useful as reagents from which the corresponding N-oxides are produced, such oxides also possessing surface active and textilesubstantive properties.

From the time of the first commercial marketing of synthetic organic detergents and surface active agents to replace the previously conventional water-soluble higher fatty acid soaps, extensive research has been undertaken in an effort to discover improved detergents and to formulate compositions containing them, with the object of obtaining better and more convenient washing agents. As a result of such research a great variety of types of surface active agents and detergents has been discovered and many of them have been manufactured commercially and have been introduced to nationwide markets. As better detergents have been made, the public has wanted to obtain additional benefits from them. Thus, research efforts have been directed to discovering products which perform additional functions, other than cleaning. For example, as the desirability of effectively washing in cold water has been recognized by consumers, research has been done and detergent compositions have been discovered which would be capable of successfully cleaning and washing textiles and laundry in cold water, as well as in hot water. Such washing capabilities are important in making a product useful for washing wool and other shrinkable materials, while at the same time being effective in ordinary hot water washing processes. In addition to making wash whiter and cleaner, it has recentl been found important to make it feel softer. As softening agents have been introduced to the market, consumers have accepted them and have wanted them to be even easier to use than has been the case in the past. Thus, although there is still a good market for textile-softening compositions which are applied in the final rinse, many house wives would prefer to be able to add the softener with the detergent, and thereby save the extra step of adding the softening agent after completion of washing, during the rinse. Such an elimination of an operation would free the housewife for tending to other tasks, after starting of the washing machine. Otherwise, she would have to stay at the washing machine to be available to add softener in the rinse water. Because of the foregoing considerations, more effective softeners have been in demand, which would be capable of being added with the detergent and would not require separate addition to the rinse.

The present compounds were found to be useful surface active agents. They possess detergent activities in both hard and soft waters, at both elevated and lower temperatures, with little clogging foam being produced. In addition, they are excellent softeners of textiles, even when added in the washing step, rather than in the rinse, in a machine-laundering operation. Such activity shows a high degree of substantivity of the products, which is considered to be unpredictable and unexpected in a surface active material that functions to release absorbed and adsorbed substances from textiles and laundry being washed. The present compounds alsopossess anti-static properties, which increase their utility as treatments for clothes and fabrics.

In accordance with the present invention, there are provided novel compounds of the formula which are effective detergents and which also serve to soften fibrous materials, such as cotton, wool and synthetics, e.g., nylon, when applied to them, as in an aqueous wash solution. In the formula R is an aliphatic hydrocarbon radical of 10 to 20 carbon atoms, R is a hydrocarbon radical of 1 to 4 carbon atoms, R is a divalent aliphatic or aromatic hydrocarbon radical of 1 to 9 carbon atoms and X is hydrogen or a salt-forming metal or ion. When X is an element, it is preferred that it should be an alkali metal, an alkaline earth metal or other suitable salt-forming metal, capable of making the present compounds water soluble. If it is a radical, it is preferred that such should be ammonium, alkylamine or alkanolamine, either mono-, dior tri-alkylamine or mono-, dior tri-alkanolamine, in which the alkyl and alkanol groups of the salt-forming amines are of 1 to 4 carbon atoms, preferably of 2 to 3 carbon atoms.

In preferred embodiments of the invention, the compounds are those Where R is an acyclic saturated radical of 12 to 16 carbon atoms, most preferably linear and terminally joined to the rest of the molecule, R is methyl, R is of 1 to 2 carbon atoms, most preferably of one carbon atom, and X is a monovalent metal or an alkanolamine, e.g., sodium potassium, diisopropanolamine or triethanolamine.

With respect to X in the above formula, it will be seen that no allowance has been made for it to be indicated as a divalent or polyvalent salt-forming ion. As shown, it is intended that the formula should cover compounds Wherein X stands for such ions and therefore, it may be considered that X represents a monovalent portion of any suitable salt-forming ion. Thus, if a divalent ion, such as magnesium, is employed, it could be joined to carboxylic groups of two aminoacid moieties. Similarly, aluminum could be joined to three such groups. In some instances, one of the ionic bonds of the polyvalent or divalent ion might be otherwise satisfied, as with a different anion. Compounds are within the invention wherein such a divalent or polyvalent ion is joined to dilferent aminoacid moieties. Of course, in addition to the mixed salts formed, mixtures of different aminoacid salts within the present invention may also be used.

The preferred compounds mentioned above are found to be excellent as textile softeners, especially for cotton articles, which may be washed with them, even in the presence of builders, other detersive compounds and additives. They may also be used in normal washing procedures, including the rinsing operation. With respect to the softening properties noted, most preferred compounds are the salts of N-(Z-hydroxy-higher alkyl)-N-lower alkyl-aminocarboxylic acids, wherein the higher alkyl is of 14 to 18 carbon atoms. Of these compounds, it is now preferred to employ N-(Z-hydroxy-higher aIkyD-N-methyl glycines, especially the alkali metal salts thereof, of which the sodium salts salts are most preferred. These compounds possess surprisingly effective textile-softening action, especially with cotton, even when applied to the textiles or laundry in the washing operation and even when the active synthetic organic detergent materials are the present compounds, with no auxiliary organic detergent being employed. Although the preferred and highly preferred embodiments of the invention have been described above, which compounds have exceptionally good softening activities on textiles and laundry, other compounds within the scope of the present invention are also useful as surface active agents, Wetting agents, emulsifiers and detergents, although they might not produce to the same extent extremely desirable softening activity shown by the most preferred compounds. In fact, in some instances, such compounds are only slightly etfective or may be essentially ineffective as practical softeners, although they will often have the unexpected advantage of being very useful because of their other surface active properties, such as detergency, often in both hard and soft waters and at elevated and comparatively low washing temperatures.

Among the compounds within the scope of the formulas previously given are N (Z-hydroxyoctadecyl)-N-methy1 glycine, sodium salt; N-(Z-hydroxyhexadecyl)-N-methy1 glycine, sodium salt; N-(Z-hydroxytetradecyl)-Nmethyl glycine, sodium salt; N-(Z-hydroxyoctadecyl)-N-ethyl glycine, potassium salt; N-(Z-hydroxyoctadecyl)-N-n-buty1- glycine, triethanolamine salt; N-(2-hydroxyoctadecyl)-N- isopropylaminopropionic acid, magnesium salt; N-(Z-hydroxyhexadecyD-N-methyl amino-n-butyric acid, triisopropanolamine salt; N (Z-hydroxyoctadecenyl)-N-ethyl aminobenzoic acid, lithium salt; N-(2-hydroxytetradecyl)- N-t-butyl amino-o-toluic acid, aluminum salt; N-(Z-hydroxytetradecyl) -N-methyl aminocyclohexanoic acid, sodium salt; mixed calcium salt of N-(Z-hydroxytetradecyl) -N- methyl glycine and N (2-hydroxyhexadecyl)-N-methyl glycine; mixed aluminum salt of N-(Z-hydroxytetradecyD- N-methyl glycine, N-(Z-hydroxyhexadecyl)-N-methyl glycine, and N (Z-hydroxyoctadecyl)-N-methyl glycine; N (2 hydroxyoctadecyl)-N-methyl glycine, calciumacid salt; N (Z-hydroxyhexadecyl)-N-methyl glycine; N-(Z-hydroxyoctadecyl)-N-ethyl aminopropionic acid; N- (Z-hydroxydodecyl)-N-methyl amino-n-nonanoic acid, diethanolamine salt; N (Z-hydroxydodecyl)-N-isopropyl amino-isopropylbenzoic acid, trimethylamine salt; N-(Z- hydroxy-propylene tetramer)-N-ethyl aminobutyric acid,

sodium salt; N-(Z-hydroxy-mixed straight chain alkyl of 14 to 18 carbon atoms)-N-methyl glycine, lithium salt; N (Z-hydroxy-6-isopropyl-n-decyl)-N-methy1 aminopropionic acid, calcium salt; N-(2-hydroxydocosyl)-N-methyl glycine, sodium salt; N-(Z-hydroxy-d-cyclohexyl-n-octyl)- N-methyl glycine, sodium salt; and N-(2-hydroxyoctadec yl)-N-methyl glycine, trimethylamine salt.

The above-mentioned compounds are illustrative of those within the formulas given but it will be clear to those of skill in the art that other compounds are within the scope of such formulas and are also useful. In many cases, they may posses properties superior to those specifically listed above. Also, variations may be made in the above specific compounds, wherein other mentioned constituents are employed to replace those specifically illustrated. In some cases, additional non-interfering substituents may be present, usually on the longer chain portions of the molecules, such as on the R group, Where they do not affect the properties of the final product as significantly as they might if placed on shorter chain portions. Among useful substituents are amino, hydroxy, halogen, e.g., chlorine, bromine, fluorine, and hydroxy-lower alkyl wherein the alkyl is up to four carbon atoms. The number of such substituents present will usually be small, often no more than four per molecule and usually, less than three. It is generally preferable that compounds be unsubstituted but many of the substituted compounds are often of utilities similar to those of the compounds literally within the formulas given and therefore, are also contemplated as relevant to this invention. As has been illustrated by recitation of the specific compounds Within the formulas given above, mixed salts maybe employed, as may be acid salts.

From the recitation of the above compounds, it is seen that the hydrocarbyl groups, R include both saturated and relatively slightly unsaturated radicals. Thus, one or two double bonds per R are acceptable and are within the present invention, although it is preferred to employ alkyl groups as R Of the alkyl groups, straight chain alkyls, which are terminally joined to the carbon to which the hydroxy group is attached, are highly preferred, and are intended to be described herein, unless otherwise indicated, although those alkyl groups which are not terminally joined also possess utility, as do various alkyl groups of nonlinear structures. For example, medially joined keryl (alkyl derived from kerosene) may he used for R Also useful are various polymeric radicals, such as propylene tetramer and pentamer, a preferred form of which is often such a mixture thereof as to average 13 carbon atoms per group. In some instances, it may be desirable to have cycloalkyl groups employed, either alone or with linear alkyls, e.g., cyclohexyldecyl. In R it is important that the hydrocarbyl radical be short chain. Although a single double bond may be tolerated in such groups, it is preferred that they be alkyl and of the alkyls, those of one and two carbon atoms are much preferred, with the methyl radical being considered as the best. R may also include one or two aliphatic double bonds and may possess aromatic unsaturation. Again, although aromatic groups such as phenyl, are useful and within the invention, as are cycloaliphatic groups, e.g., cyclohexyl, cyclobutyl, it is preferred to employ linear alkylene, terminally joined to the amino nitrogen and the carboxyl group. Although X may be hydrogen, it is preferred that it be a salt-forming ion and of the salt-forming ions those which are monovalent are usually best. The salts made tend to be more stable and freer flowing than the acids and because of this and because the product is most frequently employed in alkaline solutions, the salts are preferable. However, even if water solubility is low, salts of such solubility can be employed in other polar media and may even be useful in aqueous media, especially if solvents or solubilizers are present.

The novel compounds of the present invention can be prepared by reacting a hydrocarbon-1,2-epoxide with an N-substituted aminocarboxylic acid. Such reactions are in accordance with the equation.

The reaction normally goes in aqueous solution wherein the aminoacetic acid, as a salt dissolved in the aqueous medium, is mixed with an approximately stoichiometric proportion of the hydrocarbon-1,2-epoxide. An additional solvent, such as alcohol, may be employed. Usually, the reaction mixture is heated, often to about the boiling point, to speed the reaction. After cooling, water may be removed therefrom by any convenient means, e.g., freeze drying, and if desired, the product may be recrystallized, as from alcohol.

The N-substituted aminoacids and their salts are known compounds, as are the hydrocarbon epoxides. Methods for making such compounds from readily available starting materials are known to those of skill in the art and accordingly, they need not be described herein. In the reaction of although stoichiometric proportions are preferred, it is within the present invention to use an excess of either reagent, depending upon the circumstances, with the usual excess not exceeding 50% and only in rare cases being in excess of 20%. Sometimes an excess of a reagent, such as the epoxide, results in an impure product, in which cases use thereof is avoided. Generally, the excess employed will be no more than Although the reactions may be effected at various temperatures, depending upon the particular reagents, it is normally preferred that during at least part of the reaction, the reaction mixture should be at a temperature within the range of 60 C. to 170 0, preferably 70 C. to 130 C. The reagents will usually be admixed at a lower temperature, often approximating room temperature. Such lower temperature will usually be within the range of C. to 40 C. The times of contact of the reagents with each other at the temperatures mentioned will normally be 15 seconds to one hour at the lower temperature and subsequently, from five minutes to 24 hours at the higher temperature. Preferably, the time of contact at the lower temperature will be from one minute to ten minutes and at the higher temperature it will be from minutes to four hours. The reaction medium will usually be aqueous and one or both of the reagents may be admixed with the other as an aqueous solution or suspension. Generally, it is preferred that the aminoacid salt be employed, in aqueous solution. Although the proportion of water in the reaction mixture may be variable, it will usually be within the range of from 20 to 90% of the reaction mixture.

After holding at the higher temperature, preferably the boiling or reflux temperature, for sufiicient time for completion of the reaction, which is often evidenced by thickening of the product, the reaction mixture is cooled and the water present is removed by a suitable technique, such as by freeze drying, evaporation, distillation, or selective extraction, depending upon the particular materials being employed. The product resulting, usually present as a residue, may be deoiled with lower ketone, preferably boiling acetone, which removes n'onsalts, such as epoxide, olefins and byproducts e.g., diols. The residue left is a white solid in most cases, the desired product. This may then be recrystallized from a suitable solvent, such as a lower alcohol, e.g., absolute ethanol. The lower ketone is of 3 to 6 carbon atoms, and the alcohols are usually of 1-6 carbon atoms. The products produced are usually white and are sufficiently free-flowing to be successfully employable as detergent compositions or textile softeners, either by themselves or with other materials.

Although it is preferred to use the reactants in aqueous solution, other solvents may be used, either in place of or in conjunction with water to help to dissolve the reactants, by formation of a solvent pair. Such solvents include acetone, lower alcohols of l to 4 carbon atoms, glycols and other known suitable solvents for reactions such as this.

The novel compounds made according to the present invention are usually employed in aqueous solution, either alone or with other materials, to produce improved detersive compositions or emulsions and to act as wetting agents. They are also used in such compositions to soften fabrics, especially cotton textiles, although they also act to improve the feel of other fabrics, including wool and synthetics. In many processes the invented compounds usefully wash and soften textiles in a single operation. Such activities, wherein the softening agents are eifective despite being added to the wash water, rather than to the rinse water and wherein they themselves act to remove other substances from the fibers or laundry being washed, in the cleaning process, are considered to be unusual and unpredicatable. The softening effect appears to depend to a significant extent upon the substantivity of the invented compounds to the various fibers. As a result of such dual utility, many of the present compounds are very useful in combination detergent-softener compositions. The advantages of such compounds, as opposed to separate detersive and softening materials, have been discussed previously.

The following examples are given to illustrate the invention but are not considered to be limiting it. Unless, otherwise stated all parts given in the examples and elsewhere in the specification are by weight.

EXAMPLE 1 400 parts of n-dodecane-l,2-epoxide and 700 parts of a 32% aqueous solution of sodium N-methyl glycinate are admixed with vigorous stirring at room temperature (25 C.) over a period of two minutes. Then, the reaction mixture is heated to a boil at C. and heating is continued with reflux for one hour, until the mixture becomes too viscous to boil. The reaction mixture is then cooled to room temperature, after which it is frozen and moisture vapor is removed by sublimation (freeze drying). The residue remaining is treated several times with a total of 1000 parts of boiling acetone. The deoiled residue is dissolved in 800 parts of absolute ethanol at a temperature of 7 0 C. The solution is filtered, and upon coolmg, purified N-(2-hydroxylauryl)-N-methyl glycine, sodium salt, melting point, l28-13'0 C., crystallizes from the alcohol solution. The yield resulting is 590 parts, which is almost the stoichiometric quantity.

The chemical identity of the product is ascertained by titration with hydrochloric acid of know normality, indicating that the molecular weight of the product is about 300. Titration with perchloric acid in acetic acid indicates an equivalent weight of about 150. The theoretical molecular and equivalent weights are 295 and 148, respectively. An infrared spectrum of the compound shows a band at 3.1 microns, indicating the presence of hydroxyl, and gtgtg bands at 6.2 and 7.1 microns, indentifying the When, in place of the sodium salt, the glycine salt employed is an ammonium salt, a diammonium salt, a triethanolamine salt, a mixture of sodium and potassium salts, or a diisopropylamine salt, and the same general method for manufacture described above is employed, the corresponding N-(Z-hydroxyalkyl)-N-methyl glycinates are obtained. In such reactions stoichiometrically equivalent amounts of such glycinate reagents will be employed.

. The procedure of Example 1 is also carried out, utilizmg different aminoacetic acid salts, such as N-methyl aminopropionic acid, sodium salt; N-ethyl aminobutyric acid, potassium salt; N-isopropyl amino-n-pentanoic acid,

mixture of sodium and potassium salts; N-methyl aminobenzoic acid, triethanolamine salt; and N-butyl amino-otoluic acid, triethylamine salt; with the desired N-(2-hydroxyhydrocarbyl)-lower alkyl aminocarboxylates resulting. Corresponding products are obtained when the starting epoxides are n-myristyl-l,2-epoxide; n-hexadecane- 1,2-epoxide; cyclohexyldecane-l,2-epoxide; and propylene tetramer-1,2-epoxide. In some cases the times of reaction are extended or temperatures are increased to promote reaction, whereas in other instances a shorter time is needed and lower temperatures are employed. Such modifications of the manufacturing methods will be evident to those of skill in the art. Also, methods of recovering the desired product may be varied in specific situations to promote obtaining the best yields of purest compounds.

EXAMPLE 2 342 parts of a 32.4% solution of sodium N-methyl glycinate are admixed with 212 parts of n-tetradecane- 1,2-epoxide, with vigorous stirring, at room temperature, over a period of three minutes. The reaction mixture is then heated under reflux, utilizing a foam trap, for a period of 45 minutes, until the mixture becomes too viscous for further heating and foaming becomes excessive. At this point heating is stopped and the reaction mixture is allowed to cool, after which it is frozen and the water is removed therefrom by freeze-drying. Unreacted epoxide is extracted by heating the dried product two or three times, each time with approximately 200 parts of boiling acetone. The residue is taken up in 500 parts of absolute ethanol and the alcohol-insolubles, which include unreacted sodium N-methyl glycine, are removed by centrifuging the solution at 60 C. The solution is then allowed to cool and the desired product,

N-(2-hydroxy-n-tetradecyl)-methyl glycine, sodium salt, crystallizes and is separated by filtration. The product resulting, recrystallized from absolute ethanol, is a completely water soluble white powder which possesses strong foaming action. Its melting point is 119-123 C.

When the same method is employed, starting with 240 parts n-hexadecyl-l,2-epoxide, with the exception of recrystallization from isopropanol, rather than ethanol, there is obtained the corresponding N-(Z-hydroxy-n-hexadecyl)-N-rnethyl glycine, sodium salt, which has a melting point of 89-9l C. and which is soluble in Water upon heating and foams to a desired limited extent.

When the method followed for the manufacture of N (2 -hydroxy-n-hexadecyl)-N-methyl glycine, sodium salt, is also followed, except for the use of 268 parts of n-octadecyl-l,2-epoxide, the product obtained is a white powder of a melting point of ll41l7 C., which is found to be substantially insoluble in water at room temperature but which makes a viscous solution when heated. This product does not foam well.

EXAMPLE 3 The method of Example 1 is followed, using equimolar proportions of the reagents, sodium sarcosine and mixed normal C1548 olefin oxide. The oxygen is present across a terminal bond of the olefin, making an epoxide corresponding to those previously recited, except for being based on mixed olefin, rather than being a substantially pure material. After completion of the reaction, water is removed by freeze drying. The product resulting is not purified further.

Similarly, a mixed C1144 alkyl alpha-epoxide, having as an average a molecular weight of 210, is reacted with sodium sarcosinate, utilizing about a 10% excess of the sareosinate. In this reaction, 315 parts of the mixed epoxides and 600 parts of 30% aqueous solution of sodium sarcosinate are stirred together and heated to boiling, 105-110" C. After 30 minutes, the reaction mixture becomes viscous and 200 parts of cold water are added to quench the boiling mixture. The mixture is stirred at 100 C. for two more hours to insure complete reaction.

Much of the water evaporates and the product resulting is comprised 60% of the desired active ingredient, the N-(2-hydroxy-C alkyl)-sarcosine, sodium salt. Such material may be subsequently oxidized by gradual addition, with stirring, of 180 parts of a 30% aqueous hydrogen peroxide solution. The product obtained comprises 65% of the corresponding N-oxide.

EXAMPLE 4 The compounds described in Examples 1 and 2 are tested for their utilities as textile softeners and as detergents. Although various of these compounds have excellent detersive and softening effects, the best effects appear to be obtained from N-(2-hydroxy-higher alkyl)- N-methyl glycine, sodium salt, wherein the higher alkyl is of 14 to 18 carbon atoms, is straight chain and is terminally joined to the nitrogen atom.

When tested as fabric softeners, N-(Z-hydroxyoctadecyl)-N-methyl glycine, sodium salt, N-(Z-hydroxyhexadecyl)- I-methyl glycine, sodium salt, N-(Z-hydroxytetradecyl)-N-methyl glycine, sodium salt, and N-(Z-hydroxydodecyl)-N-methyl glycine, sodium salt obtain ratings of 10+, 10, 8 and 3, respectively, indicating their softening effects on cotton. They also impart anti-static properties to the cotton. The test by which they are evaluated for softening action is one in which one-half of a terrycloth towel is washed in 3 gallons of 10 p.p.m. hardness water, at F. by a detergent composition comprising 6.6 grams of sodium tripolyphosphate and 2 grams of N- (2- hydroxy-higher alkyl)-N-methyl glycine, sodium salt. After being washed in the mini-basket of a General Electric Company automatic washing machine, in the described detergent solution, the towel is rinsed in the usual manner and is essentially freed of wash water, after which it is dried and softness is rated. The softness scale employed is 1 to 10, with 1 indicating a towel that is not soft and 10 indicating excellent softening effects. Employing such a rating system, it is seen that a very significant softening is obtained from the use of N-(2-hydroxyoctadecyl)-N-methyl glycine, sodium salt.

The compounds of Examples 1 and 2 are also evaluated for their activities as synthetic detergents. The results are indicated in Table 1.

TABLE 1.SPANGLER SOIL DETERGENCY TESTS A Rd (soil removal) The Spangler soil detergency tests are run using 15% of each of the mentioned compounds, 35% sodium tripolyphosphate and 50% sodium sulfate, to make a textilesoftening and detergent composition. In these tests, the concentration of such washing preparation employed is 0.15% in water, which corresponds to the recommended usage of such materials in a home washing machine. Three cotton percale swatches, each 3 inches by 6 inches, are first soiled with Spangler soil, which is a mixture of airborne and sebum soils. They are then washed in a Tergotometer evaluating washing machine, using waters of two ditferent hardnesses, at two different temperatures, as indicated. After Washing, the swatches are rinsed and are tested for whiteness, using a color difference meter. The comparison of readings, using the R scale, between the materials before and after washing, is made and the delta R is calculated. The greater the delta R the more efficient is the soil removal and the better is the detergency obtained. Linear tridecyl benzene sulfonate, as the sodium salt, is usually employed as a standard of comparison for detergency in this test.

From the data, as reported in Table 1, it is apparent that the novel compounds of this invention described herein are useful detergents. They are especially satisfactory detergents in an ordinary city water, such as New Brunswick tap Water, in both high and low temperature washing. Similar results are obtained with other compounds of this invention, previously described in the specification. In very hard water, the N-(Z-hydroxyoctadecyl)-N-methyl glycine, sodium salt, is most effective of the compounds tested, as higher washing temperatures.

EXAMPLE 19.5 lbs. of a normal hexadecane-1,2-epoxide are charged to a pressure reaction vessel together with 44 lbs. of a 32% aqueous solution of sodium sarcosine and 1 lb. 6 oz. of a 43% aqueous solution of sodium cumene sulfonate. The pressure vessel, a Blew-Knox autoclave, is sealed after mixing of the reactants and the temperature is raised to about 330 F. by passing steam at a pressure of 90 lbs/sq. in. through the autoclave jacket.

After minutes heating under pressure the production of N-(2-hydroxy-hexadecyl)-N-methyl glycine, sodium salt, is essentially complete, as is shown by analysis of the product. Thus, the reaction is significantly promoted by conducting it under pressure at the elevated temperature. Also, the pressure assists in discharging the reaction product from the vessel.

Similar reactions at elevated temperatures and pressures, utilizing previously mentioned higher alkane epoxides and salts of N-substituted aminocarboxylic acids are conducted to produce various other N-(Z-hydroxyhigher hydrocarbyl)-N-alkyl carboxylates of this specification, with speeding of the reactions. Temperatures and pressures may be varied but are usually from about 250 F. to 450 F. and about to 300 lbs./sq. in. gauge. Reaction times are usually from 5 minutes to minutes. Other hydrotropes than the sodium cumene sulfonate are also useful but when the eflects thereof are not desired they may be omitted.

The present invention has been described in conjunction with various illustrations and embodiments thereof set forth in the specification. However, it is evident that equivalents may be substituted for the present compounds and procedural steps, without departing from the principles of this invention or the spirit thereof. Those of 10 skill in the art will recognize equivalents and substitutes that are also within the scope of the present disclosure.

What is claimed is:

1. Compounds of the formula:

wherein R is an aliphatic hydrocarbon radical of 10 to 20 carbon atoms, containing at most, 2 aliphatic double bonds, R is a hydrocarbon radical of 1 to 4 carbon atoms, containing at most, a single aliphatic double bond, R is a divalent aliphatic hydrocarbon radical, containing at most, 2 aliphatic double bonds or aromatic hydrocarbon radical of 1 to 9 carbon atoms and X is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, ammonium, monoalkylamine, dialkylamine, trialkylamine, monoalkanolamine, dialkanolamine, and trialkanolamine, in which the alkyl and alkanol groups are 1 to 4 carbon atoms.

2. Compounds according to claim 1 wherein R is an acyclic radical and R is an aliphatic radical.

3. Compounds according to claim 2 wherein R is alkyl, terminally joined to the rest of the molecule, R is alkyl of 1 to 2 carbon atoms, R is alkylene of 1 to 4 carbon atoms and X is monovalent.

4. Compounds according to claim 3 wherein R is of 12 to 16 carbon atoms, R is methyl, R is alkylene of 1 to 2 carbon atoms and X is alkali metal or triethanolamine.

5. Compounds according to claim 4 wherein R is methylene and X is an alkali metal.

6. A compound according to claim 4 wherein R is of 16 carbon atoms and X is sodium.

References Cited Finar, I. L., Organic Chemistry, vol. I (1963), pub. by

Richard Clay Co. of England, QD251F56, p. 252 relied on L. A. THAXTON, Assistant Examiner US. Cl. X.R. 260404, 501.11, 519 

